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Optical disc device varying, detecting and noticing a recording velocity during a recording
7020058 Optical disc device varying, detecting and noticing a recording velocity during a recording
Patent Drawings:Drawing: 7020058-2    Drawing: 7020058-3    Drawing: 7020058-4    Drawing: 7020058-5    
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Inventor: Yamamoto
Date Issued: March 28, 2006
Application: 10/132,380
Filed: April 26, 2002
Inventors: Yamamoto; Kazutaka (Kanagawa, JP)
Assignee: Ricoh Company, Ltd. (Tokyo, JP)
Primary Examiner: Hindi; Nabil
Assistant Examiner:
Attorney Or Agent: Dickstein Shapiro Morin & Oshinsky LLP
U.S. Class: 369/47.29; 369/47.38; 369/47.43
Field Of Search: 369/47.38; 369/47.32; 369/47.33; 369/47.39; 369/47.43; 369/47.45; 369/47.34; 369/47.27; 369/47.29; 369/47.36; 369/47.4; 369/47.1; 369/53.22
International Class: G11B 7/00
U.S Patent Documents: 5463604; 5553042; 6115342; 6154428; 6570831; 6714509; 6728177; 6751174; 6862258; 2001/0003519
Foreign Patent Documents: 0 872 837; 0 929 072; 1 081 696
Other References:









Abstract: An optical disc device records data on an optical disc by projecting a laser beam on the optical disc such that a linear density of the data becomes substantially constant. The optical disc device comprises velocity judging means, velocity changing means, recording velocity detecting means, and recording velocity transmitting means. The velocity judging means is for judging a recordable velocity for an optical recording medium inserted into the optical disc device. The velocity changing means is for changing a recording velocity designated from a host. The recording velocity detecting means is for detecting the recording velocity during a recording. The recording velocity transmitting means is for transmitting information concerning the detected recording velocity to the host.
Claim: What is claimed is:

1. An optical disc device recording data on an optical disc by projecting a laser beam on said optical disc such that a linear density of the data becomes substantiallyconstant, the device comprising: one of first recording means and second recording means for recording the data, the first recording means varying a recording velocity gradually, and the second recording means changing a recording velocity according asrecording areas on said optical disc; recording velocity detecting means for detecting said recording velocity during a recording performed by one of said first recording means and said second recording means; and recording velocity transmitting meansfor transmitting information concerning said recording velocity to a host, said recording velocity being detected by said recording velocity detecting means.

2. An optical disc device recording data on an optical disc by projecting a laser beam on said optical disc such that a linear density of the data becomes substantially constant, the device comprising: velocity judging means for judging arecordable velocity for an optical recording medium inserted into said optical disc device; velocity requesting means for receiving a command requesting a recording velocity from a host during a recording; recording velocity detecting means fordetecting said recording velocity during said recording; and recording velocity transmitting means for transmitting information concerning said recording velocity to said host, said recording velocity being detected by said recording velocity detectingmeans.

3. The optical disc device as claimed in claim 2, wherein said velocity changing means changes said recording velocity designated from said host to said recordable velocity judged by said velocity judging means when said recording velocity isequal to or higher than said recordable velocity.

4. The optical disc device as claimed in claim 1, wherein said recording velocity detecting means comprises: synchronizing signal counting means for counting ATIP synchronizing signals included in a wobble signal, where said ATIP synchronizingsignals represent absolute time information; and recording velocity calculating means for calculating said recording velocity from a number of said ATIP synchronizing signals counted within a predetermined time.

5. The optical disc device as claimed in claim 2, wherein said recording velocity detecting means comprises: synchronizing signal counting means for counting ATIP synchronizing signals included in a wobble signal, where said ATIP synchronizingsignals represent absolute time information; and recording velocity calculating means for calculating said recording velocity from a number of said ATIP synchronizing signals counted within a predetermined time.

6. The optical disc device as claimed in claim 1, wherein said recording velocity detecting means comprises: buffer pointer monitoring means for monitoring a buffer pointer used for transmitting record data; and recording velocity computingmeans for computing said recording velocity from a value of said buffer pointer varied within a predetermined time.

7. The optical disc device as claimed in claim 2, wherein said recording velocity detecting means comprises: buffer pointer monitoring means for monitoring a buffer pointer used for transmitting record data; and recording velocity computingmeans for computing said recording velocity from a value of said buffer pointer varied within a predetermined time.

8. The optical disc device as claimed in claim 1, wherein said recording velocity transmitting means transmits said information concerning said recording velocity to said host by using a mode sense command allowed to be issued during arecording.

9. The optical disc device as claimed in claim 2, wherein said recording velocity transmitting means transmits said information concerning said recording velocity to said host by using a mode sense command allowed to be issued during arecording.
Description: BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention generally relates to an optical disc device, and more particularly, to a technology for a host to obtain in real time a current recording velocity of an optical disc device varying the recording velocity during a recordingto an optical disc, chiefly a CD-R or a CD-RW.

2. Description of the Related Art

In general, optical recording media can be classified into the following three types, depending on whether or not data can be recorded thereon repeatedly: a ROM type used only for reproduction, a write-once-read-many WORM type, and a rewritabletype on which data can be recorded repeatedly. The ROM-type optical recording media include a CD-ROM (Compact Disc-Read Only Memory) and a DVD-ROM (Digital Versatile Disc-Read Only Memory). The WORM-type optical recording media include a write-onceCD-R (Compact Disc-Recordable) and a write-once DVD-R (Digital Versatile Disc-Recordable). The rewritable-type optical recording media, on which data can be recorded freely and repeatedly, include a CD-RW (Compact Disc-Rewritable), a DVD-RAM (DigitalVersatile Disc-Random Access Memory) and a DVD-RW (Digital Versatile Disc-Rewritable).

A driver device that records information on a medium having tracks in a spiral form, represented by the above-mentioned CD-R/RW, generally adopts a Constant Linear Velocity (CLV) method. However, since a conventional device records only at aslow recording velocity, there has not been a problem that a mechanical characteristic of a medium inhibits a maximum-velocity recording. Accordingly, a recording is always performed at a velocity designated from a host, and the host can inform anoperator of the designated velocity as a recording velocity. In other words, the drive device does not have to return current recording velocity information to the host during a recording.

Recently, however, a recording velocity of the above-mentioned CD-R/CD-RW drive device has rapidly been developed higher. The recording velocity is now beginning to undergo an evolution similar to an evolution of a reproducing velocity in whichthe reproducing velocity is increased from a limit of revolutions in a 16-fold velocity CLV reproduction to a greater degree by a PCAV (Partial Constant Angular Velocity) reproduction and a CAV (Constant Angular Velocity) reproduction, without increasingthe revolutions. For example, in a recording at a 20-fold velocity at a maximum, a ZCLV (Zone Constant Linear Velocity) recording is conceivable in which data is recorded by a 16-fold velocity CLV unto a 10-minute position, and by a 20-fold velocity CLVfrom the 10-minute position. Also, a PCAV (Partial Constant Angular Velocity) recording is conceivable in which data is recorded by a CAV from a 16-fold velocity to a 20-fold velocity, and once the velocity reaches the 20-fold velocity, data is recordedtherefrom by a 20-fold velocity CLV.

In addition, as basic recording modes for the CD-R/CD-RW, there are a disc-at-once mode and a track-at-once mode. These modes are sequential writings which do not cause an interruption of recording unless a buffer underrun occurs. Accordingly,a time required for a recording can be easily conjectured from a recording velocity and a recording capacity. A host can inform an operator of the recording velocity and the time required for the recording so that the operator can perform systematicoperations. This is a feature that a storage device performing a random writing does not possess.

Besides, a motor has a limit of revolutions partly because a focus and track servo cannot be performed correctly at a high-speed revolution. This depends greatly on a formation precision of media such that the servo cannot possibly be performedcorrectly even at a 16-fold velocity for an inferior medium.

Whereas a high-speed recording is realized by improvements in performance of both a drive and media, a safe recording is preferable with whatever media. This highlights an importance of a technology in which a drive device perceives a limit ofmedia so as to record data at a safe velocity, the technology being put to practical use. For example, a maximum recording velocity is restricted according as types of media; or servo status is checked before writing so as to determine a safe velocity.

As mentioned above, conventionally, a drive device records data from the start to the end at a velocity designated by a host, which did not cause a particular problem. However, now that a recording velocity is increased variably, there occurs adifference between a velocity designated by a host and a velocity at which a drive device actually records data, which makes it difficult for an operator to conjecture a time required for a recording.

SUMMARY OF THE INVENTION

It is a general object of the present invention to provide an improved and useful optical disc device in which the above-mentioned problems are eliminated.

A more specific object of the present invention is to provide an optical disc device which enables a host to obtain recording velocity information at any time during a recording.

In order to achieve the above-mentioned objects, there is provided according to one aspect of the present invention an optical disc device recording data on an optical disc by projecting a laser beam on the optical disc such that a linear densityof the data becomes substantially constant, the device comprising:

one of first recording means and second recording means for recording the data, the first recording means varying a recording velocity gradually, and the second recording means changing a recording velocity according as recording areas on theoptical disc;

recording velocity detecting means for detecting the recording velocity during a recording performed by one of the first recording means and the second recording means; and

recording velocity transmitting means for transmitting information concerning the recording velocity to a host, the recording velocity being detected by the recording velocity detecting means.

According to the present invention, a recording velocity during a recording is detected, and the recording velocity information is transmitted to the host so that the host can recognize the current recording velocity. Additionally, since acurrent recording velocity during a recording is imparted to the host, an operator can comprehend the recording velocity at any time, even when the recording velocity varies during the recording, so as to estimate a finish time of the recording,eliminating uneasiness and irritation.

In order to achieve the above-mentioned objects, there is also provided according to another aspect of the present invention an optical disc device recording data on an optical disc by projecting a laser beam on the optical disc such that alinear density of the data becomes substantially constant, the device comprising:

velocity judging means for judging a recordable velocity for an optical recording medium inserted into the optical disc device;

velocity changing means for changing a recording velocity designated from a host;

recording velocity detecting means for detecting the recording velocity during a recording; and

recording velocity transmitting means for transmitting information concerning the recording velocity to the host, the recording velocity being detected by the recording velocity detecting means.

According to the present invention, even when the recording velocity is determined according as conditions of media, an operator can comprehend the recording velocity at any time so as to estimate a finish time of the recording, eliminatinguneasiness and irritation.

Additionally, in the optical disc device according to the present invention, the velocity changing means may change the recording velocity designated from the host to the recordable velocity judged by the velocity judging means when the recordingvelocity is equal to or higher than the recordable velocity.

According to the present invention, since the recording velocity designated from the host is compared to the recordable velocity for an optical recording medium, data can always be recorded on the optical recording medium at the recordablevelocity therefor.

Additionally, in the optical disc device according to the present invention, the recording velocity detecting means may comprise:

synchronizing signal counting means for counting ATIP synchronizing signals included in a wobble signal, where the ATIP synchronizing signals represent absolute time information; and

recording velocity calculating means for calculating the recording velocity from a number of the ATIP synchronizing signals counted within a predetermined time.

According to the present invention, the ATIP synchronizing signals are counted so as to detect a recording velocity with ease, especially during a CAV recording in which the recording velocity is varied gradually.

Additionally, in the optical disc device according to the present invention, the recording velocity detecting means may comprise:

buffer pointer monitoring means for monitoring a buffer pointer used for transmitting record data; and

recording velocity computing means for computing the recording velocity from a value of the buffer pointer varied within a predetermined time.

According to the present invention, the pointer of a buffer manager transmitting data to an encoder is used in measuring a recording velocity so as to minimize a CPU load.

Additionally, in the optical disc device according to the present invention, the recording velocity transmitting means may transmit the information concerning the recording velocity to the host by using a mode sense command allowed to be issuedduring a recording.

According to the present invention, since a standard command is used, a modification for realizing the recording velocity transmitting means can be made with minimum labor and a minimum amount of program code.

Other objects, features and advantages of the present invention will become more apparent from the following detailed description when read in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram showing a configuration of an optical disc drive device according to an embodiment of the present invention;

FIG. 2A is a graph representing a relationship between a time on disc and a recording velocity in a ZCLV recording;

FIG. 2B is a graph representing a relationship between a time on disc and a recording velocity in a PCAV recording;

FIG. 3 is a flowchart for the drive device according to the embodiment of the present invention to change a recording velocity to a safe recording velocity; and

FIG. 4 is a diagram representing mode sense data on Mode Page 2Ah according to the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

A description will now be given of embodiments according to the present invention.

FIG. 1 is a block diagram showing a configuration of an optical disc drive device 20 according to an embodiment of the present invention. The optical disc drive device 20 comprises an optical disc 1, a spindle motor 2, an optical pickup 3, an LDdriver 4, a motor driver 5, a read amplifier 6, an ATIP decoder 7, a CD encoder 8, a servo process circuit 9, a CD decoder 10, a buffer memory 11, a host interface 12, a CD-ROM decoder 13, a buffer manager 14, a CD-ROM encoder 15, and a system controller16. The optical disc 1 is a CD revolved by the spindle motor 2. The motor driver 5 drives actuators (not shown in the figure) provided in the optical pickup 3. The servo process circuit 9 generates a signal used for a servo control, and supplies thesignal to the motor driver 5. The read amplifier 6 processes each of signals supplied from a photo-receptive element (not shown in the figure) provided in the optical pickup 3. The optical pickup 3 incorporates a semiconductor laser light source foruse in a CD, an optical system such as an objective lens, and the actuators, which are not shown in the figure. The LD driver 4 controls a luminous energy, etc. of the laser light source. The ATIP decoder 7 extracts ATIP (Absolute Time In Pregroove)information engraved in the optical disc 1. The CD encoder 8 generates information concerning an accurate start position of writing data. The CD decoder 10 subjects a binarized RF signal to an EFM (Eight to Fourteen) modulation. The buffer memory 11temporarily stores data. The buffer manager 14 controls the buffer memory 11. The host interface 12 is connected to the buffer memory 11, and includes interfaces such as an ATAPI and an SCSI. The CD-ROM decoder 13 performs an error correction againwith respect to data supplied from the CD decoder 10. The CD-ROM encoder 15 adds error correction code and performs an interleave. The system controller 16 controls the above-described system as a whole.

Besides, the optical pickup 3, the read amplifier 6, the ATIP decoder 7 and the system controller 16 mainly compose recording velocity detecting means and buffer pointer monitoring means. The buffer memory 11, the buffer manager 14 and the hostinterface 12 compose recording velocity transmitting means. The buffer memory 11, the buffer manager 14 and the system controller 16 mainly compose velocity judging means and velocity changing means. The ATIP decoder 7 and the system controller 16mainly compose synchronizing signal counting means, recording velocity calculating means and recording velocity computing means.

Next, a description will be given of operations according to the embodiment of the present invention. In FIG. 1, arrows indicate representative streams of signals and data, and do not show all of connections among the above-described elements. The optical disc 1 is revolved by the spindle motor 2. The spindle motor 2 is controlled by the motor driver 5 and the servo process circuit 9 such that a linear velocity or an angular velocity becomes constant. The linear velocity or the angularvelocity can be varied by steps. The optical pickup 3 incorporates the semiconductor laser, the optical system, a focus actuator, a track actuator, the photo-receptive element, and a position sensor, which are not shown in FIG. 1. The optical pickup 3projects a laser light on the optical disc 1 so as to record data thereon or read data therefrom. Additionally, the optical pickup 3 can be moved by a seek motor. The focus actuator, the track actuator and the seek motor are controlled by the motordriver 5 and the servo process circuit 9 according to signals supplied from the photo-receptive element and the position sensor such that a laser spot is located at a target position. Upon reading data, a reproduction signal obtained by the opticalpickup 3 is amplified and binarized by the read amplifier 6, and thereafter is supplied to the CD decoder 10 where the signal is de-interleaved and is subjected to an error correction. Subsequently, this data is supplied to the CD-ROM decoder 13 to besubjected to an error correction again for the purpose of enhancing a reliability of the data. Thereafter, this data is temporarily stored in the buffer memory 11 under the control of the buffer manager 14. When the stored data is accumulated so as toform sector data, the sector data is transmitted to a host (not shown in the figure) at one time via the host interface 12. Upon writing data, data transmitted from the host via the host interface 12 is temporarily stored in the buffer memory 11 underthe control of the buffer manager 14. When the stored data is accumulated in the buffer memory 11 to a certain amount, the data starts to be written. Prior to this, however, a laser spot must be located at a start position of writing the data. Thisposition is obtained by a wobble signal engraved beforehand on the optical disc 1 by a track wobbling thereon. The wobble signal includes absolute time information called ATIP. This information can be extracted by the ATIP decoder 7. A synchronizingsignal generated by the ATIP decoder 7 is supplied to the CD encoder 8 so as to enable the data to be written from the accurate start position. The data stored in the buffer memory 11 is subjected to a process of adding an error correction code and isinterleaved in the CD-ROM encoder 15 and the CD encoder 8, and is output from the CD encoder 8 as a signal modulated into an EFM signal suited for recording. The modulated signal is recorded on the optical disc 1 by a laser beam controlled by the LDdriver 4 and the optical pickup 3. The LD driver 4 continuously controls conditions of light emission so as to record/reproduce properly, such as by making the laser beam luminous at a write power according to the EFM signal suited for recording.

FIG. 2A is a graph representing a relationship between a time on disc and a recording velocity in a ZCLV recording. FIG. 2B is a graph representing a relationship between a time on disc and a recording velocity in a PCAV recording. It is notedthat the PCAV recording mainly constitutes first recording means, and the ZCLV recording mainly constitutes second recording means. When a recording velocity for a CD-R becomes as fast as a 20-fold velocity, revolutions per minute at inner tracks exceed10,000 rpm, which makes it difficult to control an optical pickup. Thereupon, for the purpose of restraining the revolutions per minute at inner tracks, data is recorded by a CAV, PCAV or ZCLV recording exhibiting different recording velocities at innertracks and outer tracks. ZCLV, an abbreviation for Zone Constant Linear Velocity, is a recording method in which data is recorded at a constant recording velocity in each zone, the recording velocity becoming larger in outer zones. Although the ZCLVrecording exhibits a lower average velocity than the PCAV recording, the ZCLV recording is supposed to exhibit an we excellent recording quality. For example, as shown in FIG. 2A, in a recording at a 20-fold velocity at a maximum, data is recorded by a16-fold velocity CLV unto a 10-minute position, and by a 20-fold velocity CLV from the 10-minute position. PCAV, an abbreviation for Partial Constant Angular Velocity, is a recording method in which a recording velocity is gradually increased at innertracks until the velocity reaches a maximum recording velocity, after which data is recorded at a constant recording velocity. For example, as shown in FIG. 2B, data is recorded by a CAV from a 16-fold velocity to a 20-fold velocity, and once thevelocity reaches the 20-fold velocity, data is recorded therefrom by a 20-fold velocity CLV. When there is a large difference between recording velocities at inner tracks and outer tracks, the PCAV recording equals the CAV recording which includes noperiod during which data is recorded at a constant recording velocity.

When the recording velocity is not constant, an operator is anxious about at what velocity data is being recorded at present. Additionally, when data is recorded at a designated recording velocity throughout all tracks, a time required for therecording could be conjectured from an amount of the data to be recorded; however, when the recording velocity is not constant, it is difficult to conjecture the time required for the recording because the conjecturing requires a lot of information, suchas a type of a recording method and a recording capacity for each recording velocity. However, knowing a current recording velocity relieves the operator, because the operator intuits the time required for the recording through an experiential leaningeffect.

Additionally, in some cases, a high-speed recording cannot be performed to media standardized on a presumption of a low-speed recording. These cases occur due to problems in mechanical characteristics such as a side-runout and an eccentricity ofthe media, or due to problems in sensitivity of a recording film. Thereupon, in order to perform an unfailing and safe recording, the drive device is required to judge characteristics of the media so as to set a proper recording velocity. In this case,too, since data is recorded at a recording velocity different from a designated recording velocity, it is difficult to conjecture a time required for the recording, as when the recording velocity is not constant.

FIG. 3 is a flowchart for the drive device according to the embodiment of the present invention to change a recording velocity to a safe recording velocity. First, information concerning maximum recording velocities registered beforehand withrespect to principal types of discs is referred to (step S1). Next, a turbulence of a servo signal is measured at a plurality of positions in an area on which data is to be recorded. From the measurement is calculated a maximum recording velocitywithin which a light beam can be controlled correctly (step S2). Then, an OPC (Optimum Power Calibration) is performed so as to calculate a recording velocity with which data can be recorded with a write power not exceeding a maximum write power of thelight beam (step S3). Subsequently, it is judged whether or not data can be recorded at a velocity designated from a host, i.e., whether or not the above-calculated velocities are higher than the velocity designated from the host (step S4). When theabove-calculated velocities are lower than the velocity designated from the host (No in step S4), the velocity is changed to a lowest recording velocity considered to be safe (step S5). When the above-calculated velocities are higher than the velocitydesignated from the host (Yes in step S4), the data is recorded at the velocity designated from the host.

Besides, in the above-mentioned step S5, without means for noticing that the drive device has changed the recording velocity, the operator would feel very irritated that the recording is not finished after an expected time has elapsed. Thereupon, the drive device provides means for returning recording velocity information to the host during a recording. Specifically, the host issues a command requesting recording velocity information. The drive device detects a recording velocity atthat time, and transmits the recording velocity information to the host. The host receives this recording velocity information, and updates a display of writer software. According to the above procedure, the operator can confirm the current recordingvelocity.

Additionally, one of methods for detecting a recording velocity during a recording is a method of counting ATIP synchronizing signals. The ATIP synchronizing signals may be counted by inputting the ATIP synchronizing signals into a hardwarecounter, or may be counted by a CPU using software upon interruptions of the ATIP synchronizing signals. Based on the number of the ATIP synchronizing signals per second, the recording velocity can be calculated according to an expression (1) in thefollowing. In the expression (1), 2352 is the number of bytes per sector of a CD. 75 is a writing/reading velocity corresponding to a 1-fold velocity of a CD. [Recording velocity]=(Count of ATIP synchronizing signals persecond).times.2352.times.75/1000 (KB/S) (1)

Another method for detecting a recording velocity during a recording is a method of using a pointer of the buffer manager 14 transmitting data to the encoder. The above-described method of counting ATIP synchronizing signals has relativeshortcomings that hardware resources become necessary, and that interruption for each sector increases a CPU load when the recording velocity is high. The pointer of the buffer manager 14 undergoes an increment upon transmitting one sector data to theencoder. The buffer is used in the form of a ring such that the pointer is returned from the ending point to the starting point. When the pointer makes one revolution or more, the number of recorded sectors becomes unknown; therefore, the pointer needsto be monitored in an interval shorter than the one revolution. The CPU load becomes several hundred times as little as in the above-described method of counting ATIP synchronizing signals. When the buffer has an enough capacity, the pointer may beread at an interval of one second so as to calculate the number of increments of the pointer. The recording velocity can be computed according to an expression (2) in the following. [Recording velocity]=(Number of increments per second of a pointer ofa buffer transmitting data to an encoder).times.2352.times.75/1000 (KB/S) (2)

Constants in the expression (2) represent the same as in the expression (1).

FIG. 4 is a diagram representing mode sense data on Mode Page 2Ah. The command used for transmitting the recording velocity information to the host may be formed according to vendor-specific specifications. However, using a standard command setenables a modification to be completed with minimum labor and code amount. Although there are a restricted number of commands acceptable during a recording, those commands include a mode sense command. Mode Page 2Ah present at a 0th byte of thiscommand is a page representing a capability of the drive device, and has a format shown in FIG. 4. This format includes an item named "Current Write Speed Selected" at 20th to 21st bytes. This item indicates a recording velocity selected by the drivedevice aside from a recording velocity designated by the host. In the present invention, this item is used to notice a recording velocity during a recording. When the mode sense command is issued during a recording to make a request of Mode Page 2Ah,recording velocity information is set into this item, and is returned to the host.

The present invention is not limited to the specifically disclosed embodiments, and variations and modifications may be made without departing from the scope of the present invention.

The present application is based on Japanese priority application No. 2001-200228 filed on Jun. 29, 2001, the entire contents of which are hereby incorporated by reference.

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